This Regulation, based on the provisions of the Croatian Law on aquaculture, prescribes the obligation to display the plan of bluefin tuna farms, the procedure for marking related breeding facilities, the conditions and procedure for placing tuna in breeding cages, the conditions and procedure for catching tuna from the breeding cages, the transfer of tuna within the farm, the procedure for implementing random controls, the procedure for controlling the transfer of tuna, the procedure for transferring tuna between farms, dealing with dead tuna during farming and tuna below the minimum reference size for conservation in the catch, scientific research, obligations of the license holder towards regional observers at farms and for keeping documentation. This Regulation further ensures the implementation of the Regulation (EU) 2016/1627 of the European Parliament and of the Council on a multiannual recovery plan for bluefin tuna in the eastern Atlantic and the Mediterranean, and repealing Council Regulation (EC) No. 302/2009; and it is also harmonized with the Recommendation of the International Commission for the Conservation of Atlantic Tunas (ICCAT) (hereinafter: ICCAT) 21-08, which establishes a multi-year protection and management plan for bluefin tuna in the eastern the Atlantic and the Mediterranean Sea. Annexes 1-19 are part of this publication (containing designated set of forms and approval/reporting sheets).